NEUTRINO PHYSICS FROM PRECISION COSMOLOGY STEEN HANNESTAD 17 AUGUST 2010 – UNIVERSENET, COPENHAGEN e    

Fermion Mass Spectrum meVeVkeVMeVGeVTeV dsb Q =  1/3 uct Q =  2/3 Charged Leptons e All flavors 3 Neutrinos

FLAVOUR STATESPROPAGATION STATES MIXING MATRIX (UNITARY) FORTUNATELY WE ONLY HAVE TO CARE ABOUT THE MASS STATES

Normal hierarchyInverted hierarchy If neutrino masses are hierarchical then oscillation experiments do not give information on the absolute value of neutrino masses However, if neutrino masses are degenerate no information can be gained from such experiments. Experiments which rely on either the kinematics of neutrino mass or the spin-flip in neutrinoless double beta decay are the most efficient for measuring m 0 SOLAR KAMLAND ATMO. K2K MINOS

LIGHTEST INVERTED NORMAL HIERARCHICALDEGENERATE

experimental observable is m 2 model independent neutrino mass from ß-decay kinematics only assumption: relativistic energy-momentum relation E 0 = 18.6 keV T 1/2 = 12.3 y ß-decay and neutrino mass T2:T2:

Tritium decay endpoint measurements have provided limits on the electron neutrino mass This translates into a limit on the sum of the three mass eigenstates Mainz experiment, final analysis (Kraus et al.)

TLK KATRIN experiment Karlsruhe Tritium Neutrino Experiment at Forschungszentrum Karlsruhe Data taking starting early m

THE ABSOLUTE VALUES OF NEUTRINO MASSES FROM COSMOLOGY NEUTRINOS AFFECT STRUCTURE FORMATION BECAUSE THEY ARE A SOURCE OF DARK MATTER (n ~ 100 cm -3 ) HOWEVER, eV NEUTRINOS ARE DIFFERENT FROM CDM BECAUSE THEY FREE STREAM SCALES SMALLER THAN d FS DAMPED AWAY, LEADS TO SUPPRESSION OF POWER ON SMALL SCALES FROM

N-BODY SIMULATIONS OF  CDM WITH AND WITHOUT NEUTRINO MASS (768 Mpc 3 ) – GADGET 2 T Haugboelle, University of Aarhus 256 Mpc

AVAILABLE COSMOLOGICAL DATA

WMAP-7 TEMPERATURE POWER SPECTRUM LARSON ET AL, ARXIV

LARGE SCALE STRUCTURE SURVEYS - 2dF AND SDSS

SDSS DR-7 LRG SPECTRUM (Reid et al ’09)

S m = 0.3 eV FINITE NEUTRINO MASSES SUPPRESS THE MATTER POWER SPECTRUM ON SCALES SMALLER THAN THE FREE-STREAMING LENGTH S m = 1 eV S m = 0 eV P(k)/P(k,m 

NOW, WHAT ABOUT NEUTRINO PHYSICS?

WHAT IS THE PRESENT BOUND ON THE NEUTRINO MASS? STH, MIRIZZI, RAFFELT, WONG (arxiv:1004:0695) HAMANN, STH, LESGOURGUES, RAMPF & WONG (arxiv: ) DEPENDS ON DATA SETS USED AND ALLOWED PARAMETERS USING THE MINIMAL COSMOLOGICAL MODEL THERE ARE MANY ANALYSES IN THE LITERATURE JUST ONE EXAMPLE

THE NEUTRINO MASS FROM COSMOLOGY PLOT Larger model space More data CMB only + SDSS + SNI-a +WL +Ly-alpha Minimal  CDM +N +w+…… 1.1 eV 0.6 eV ~ 0.5 eV ~ 0.2 eV ~ 2 eV2.? eV??? eV ~ 1 eV1-2 eV eV eV

Gonzalez-Garcia et al., arxiv:

WHAT IS N  A MEASURE OF THE ENERGY DENSITY IN NON-INTERACTING RADIATION IN THE EARLY UNIVERSE THE STANDARD MODEL PREDICTION IS BUT ADDITIONAL LIGHT PARTICLES (STERILE NEUTRINOS, AXIONS, MAJORONS,…..) COULD MAKE IT HIGHER Mangano et al., hep-ph/

TIME EVOLUTION OF THE 95% BOUND ON N ESTIMATED PLANCK SENSITIVITY Pre-WMAP WMAP-1 WMAP-3 WMAP-5 WMAP-7

ASSUMING A NUMBER OF ADDITIONAL STERILE STATES OF APPROXIMATELY EQUAL MASS, TWO QUALITATIVELY DIFFERENT HIERARCHIES EMERGE 3+N N+3 s s A A A STERILE NEUTRINO IS PERHAPS THE MOST OBVIOUS CANDIDATE FOR AN EXPLANATION OF THE EXTRA ENERGY DENSITY

Hamann, STH, Raffelt, Tamborra, Wong, arxiv: COSMOLOGY AT PRESENT NOT ONLY MARGINALLY PREFERS EXTRA ENERGY DENSITY, BUT ALSO ALLOWS FOR QUITE HIGH NEUTRINO MASSES! 3+N N+3 See also Dodelson et al Melchiorri et al Acero & Lesgourgues 2009

Results for 5.66E20 POT Maximum likelihood fit. Null excluded at 99.4% with respect to the two neutrino oscillation fit. Best Fit Point (∆m 2, sin 2 2θ) = (0.064 eV 2, 0.96) χ 2 /NDF= 16.4/12.6 P(χ 2 )= 20.5% Results to be published. E>475 MeV Richard Van de Water, NEUTRINO 2010, June 14

WHAT IS IN STORE FOR THE FUTURE? BETTER CMB TEMPERATURE AND POLARIZATION MEASUREMENTS (PLANCK) LARGE SCALE STRUCTURE SURVEYS AT HIGH REDSHIFT MEASUREMENTS OF WEAK GRAVITATIONAL LENSING ON LARGE SCALES

Distortion of background images by foreground matter UnlensedLensed WEAK LENSING – A POWERFUL PROBE FOR THE FUTURE

FROM A WEAK LENSING SURVEY THE ANGULAR POWER SPECTRUM CAN BE CONSTRUCTED, JUST LIKE IN THE CASE OF CMB MATTER POWER SPECTRUM (NON-LINEAR) WEIGHT FUNCTION DESCRIBING LENSING PROBABILITY (SEE FOR INSTANCE JAIN & SELJAK ’96, ABAZAJIAN & DODELSON ’03, SIMPSON & BRIDLE ’04)

STH, TU, WONG 2006

STH, TU & WONG 2006 (ASTRO-PH/ , JCAP) THE SENSITIVITY TO NEUTRINO MASS WILL IMPROVE TO < 0.1 eV AT 95% C.L. USING WEAK LENSING COULD POSSIBLY BE IMPROVED EVEN FURTHER USING FUTURE LARGE SCALE STRUCTURE SURVEYS

STH, TU & WONG % CL

THIS SOUNDS GREAT, BUT UNFORTUNATELY THE THEORETICIANS CANNOT JUST LEAN BACK AND WAIT FOR FANTASTIC NEW DATA TO ARRIVE…..

FUTURE SURVEYS LIKE LSST WILL PROBE THE POWER SPECTRUM TO ~ 1-2 PERCENT PRECISION WE SHOULD BE ABLE TO CALCULATE THE POWER SPECTRUM TO AT LEAST THE SAME PRECISION! ”LSST” ERROR BARS

IN ORDER TO CALCULATE THE POWER SPECTRUM TO 1% ON THESE SCALES, A LARGE NUMBER OF EFFECTS MUST BE TAKEN INTO ACCOUNT BARYONIC PHYSICS – STAR FORMATION, SN FEEDBACK,….. NEUTRINOS, EVEN WITH NORMAL HIERARCHY NON-LINEAR GRAVITY ……………………..

512 h -1 Mpc z = 0 z = 4 EVOLUTION OF NEUTRINO DENSITY FIELD

FULL NON-LINEAR LINEAR THEORY Brandbyge, STH, Haugbølle, Thomsen, arXiv: (JCAP) Brandbyge & STH ’09, ’10 (JCAP), Viel, Haehnelt, Springel ’10, Agarwal, Feldman ’10 NON-LINEAR EVOLUTION PROVIDES AN ADDITIONAL AND VERY CHARACTERISTIC SUPPRESSION OF FLUCTUATION POWER DUE TO NEUTRINOS (COULD BE USED AS A SMOKING GUN SIGNATURE)

ALTERNATIVELY, THE POWER SPECTRUM CAN BE CALCULATED USING HIGHER ORDER PT OR SIMILAR TECHNIQUES SAITO ET AL 2008, 2009 WONG 2008 LESGOURGUES, MATARRESE, PIETRONI, RIOTTO 2009 KOMATSU & SHOJI 2010

LESGOURGUES ET AL 2009

ANOTHER IMPORTANT ASPECT OF STRUCTURE FORMATION WITH NEUTRINOS: THE NUMBER OF BOUND OBJECTS (HALOS) AS WELL AS THEIR PROPERTIES ARE CHANGED WHEN NEUTRINOS ARE INCLUDED

THE CLUSTER MASS FUNCTION WITH NEUTRINOS Brandbyge, STH, Haugboelle, Wong (arxiv: ) CLUSTER SURVEYS MAY ALSO REACH A SENSITIVITY OF ~ 0.05 eV IN THE NEXT DECADE (Wang et al. 06)

CDM 1 < p/T < 20 < p/T < 12 < p/T < 3 3 < p/T < 44 < p/T < 55 < p/T < h -1 Mpc INDIVIDUAL HALO PROPERTIES

Cold Dark Matter Neutrinos Relative change in profile for M sun Brandbyge, STH, Haugboelle, Wong

RECENTLY THERE HAS BEEN RENEWED INTEREST IN THE POSSIBLE DETECTION OF THE COSMIC RELIC NEUTRINO BACKGROUND THE MOST PROMISING POSSIBILITY IS TO USE NEUTRINO CAPTURE FROM THE C B (dating back to Weinberg ’62) E.g. ANY EXPERIMENT DESIGNED TO MEASURE THE BETA ENDPOINT (E.G. KATRIN) CAN BE USED TO PROBE THE COSMIC NEUTRINO BACKGROUND PROBLEM: THE RATE IS TINY!!! ANY EXPERIMENT OF THIS KIND WHICH MEASURED THE COSMIC NEUTRINO BACKGROUND WILL AUTOMATICALLY PROVIDE AN EXCELLENT MEASUREMENT OF THE NEUTRINO MASS

KURIE PLOT FOR TRITIUM – ASSUMES INVERTED HIERARCHY AND  13 CLOSE TO THE CURRENT UPPER BOUND WITH INFINITELY GOOD ENERGY RESOLUTION THERE WILL BE 3 DISTINCT PEAKS FROM BACKGROUND ABSORPTION AMPLITUDE OF EACH PROPORTIONAL TO

AND FINALLY: IN THE FAR DISTANT FUTURE WE MIGHT BE OBSERVING THE C B ANISOTROPY FOR SMALL MASSES IT CAN BE CALCULATED IN A WAY SIMILAR TO THE PHOTON ANISOTROPY, WITH SOME IMPORTANT DIFFERENCES: AS SOON AS NEUTRINOS GO NON-RELATIVISTIC LOW l MULTIPOLES GROW RAPIDLY, ALSO FEEDING THE HIGHER MULTIPOLES GRAVITATIONAL LENSING IS MUCH MORE IMPORTANT THAN FOR MASSLESS PARTICLES STH & Brandbyge, arXiv: (JCAP) (see also Michney, Caldwell astro-ph/ )

REALISATIONS OF THE C B FOR DIFFERENT MASSES

STH & Brandbyge, arXiv: (JCAP) ANISOTROPY ~ O(1)

CONCLUSIONS NEUTRINO PHYSICS IS PERHAPS THE PRIME EXAMPLE OF HOW TO USE COSMOLOGY TO DO PARTICLE PHYSICS THE BOUND ON NEUTRINO MASSES IS SIGNIFICANTLY STRONGER THAN WHAT CAN BE OBTAINED FROM DIRECT EXPERIMENTS, ALBEIT MUCH MORE MODEL DEPENDENT COSMOLOGICAL DATA MIGHT ACTUALLY BE POINTING TO PHYSICS BEYOND THE STANDARD MODEL IN THE FORM OF STERILE NEUTRINOS